Practice!

Sample Problem

The marine biome is

(A) the largest biome

(B) has fluctuating temperatures

(C) provides most of the earth’s oxygen

(D) has a high nutrient concentration

Solution

(A) and (C) are correct. The marine biome is the largest biome and provides most of the earth’s oxygen. It has the most stable temperatures, and it has a very low nutrient concentration because sunlight doesn’t reach most of the ocean waters, so (B) and (D) are incorrect.